'customarily-set' originates from the English word 'customarily,' which is derived from 'custom,' meaning 'a traditional and widely accepted way of behaving or doing something.'

'customarily' evolved from the Middle English word 'custum,' which was influenced by the Old French 'costume,' and eventually became the modern English word 'customarily.'

Initially, 'customarily' meant 'according to custom,' and this meaning has largely remained the same in modern usage.